一、用括号中动词的适当形式填空（两种分词的区别）。
1.My two_________(grow) children have both finished college.
2. _______(grow) children need good nourishment.
3.The_________(fall) snow was frozen hard.
4.The_________(fall) snowflakes in the sky are beautiful.
5.I love the noise of_________(fall) rain.
6.More traffic will be able to pass on the_________(widen) road.
7.Clint can't bear the smell of_________(burn) bread.
8.Stay away from the_________(burn) coal.
9.After jumping into the water, the lifeguard rescued th________(drown) child.
10.The mother of the_________(drown) child was grieved to death.
11.Dick jumped out of the way of the_________(approach) train.
12.The manager needs another copy of the_________(sign) contract.
13.The_________(return) letter had no stamps on it.
14.I've heard him_________(criticize) many times.
15.One should always be careful with_________(load) guns.
16.The composer was very happy to hear his works_________(play) by the famous orchestra.
17.Do you know the girl_________(play) the violin?
18.Today's farmers have increased milk production greatly through_________ (improve) methods of breeding, feeding and managing dairy cattle.
二、单项选择（分词的逻辑主语）。
19.Before singing the school song, _________.
A. a poem was recited
B. recited a poem
C. they recited a poem
D. they have recited a poem
20.Working like a telescope,_________the size of objects at great distances.
A. which magnifies a telephoto lens
B. a telephoto lens magnifies
C. a telephoto lens which magnifies
D. and magnifying a telephoto lens
21.Jumping into the water, _________.
A. the drowning child was rescued
B. the drowned child was rescued
C. the lifeguard rescued the drowning child
D. the lifeguard rescued the drowned child
22.After jumping out of a boat, _________.
A. the shark bites the man
B. the shark bit the man
C. the man was bitten by a shark
D. the man is bitten by a shark
23._________, the dog was fed.
A. After doing my homework
B. To have done my homework
C. After I did my homework
D. My homework was done
24._________, we went swimming.
A. Being a hot day
B. Due to a hot day
C. It was a hot day
D. The day being hot
25._________, all the quarrels came to an end.
A. The lost money was found
B. Finding the lost money
C. Because the lost money found
D. With the lost money found
26. _________James Bland, Carry Me Back to Old Virginny was adopted as the state song of Virginia in 1940.
A. Was written by
B. Writing by
C. He wrote the
D. Written by
27.Playing the trumpet with dazzling originality,_________dominated jazz for 20 years.
A. Louis Armstrong
B. the influence of Louis Armstrong
C. the music of Louis Armstrong
D. Louis Armstrong's talent
28. _________in a recent science competition, the three students were awarded scholarships totaling $21,000.
A. To be judged the best
B. Having judged the best
C. Judged the best
D. Judging the best
29. _________to steel, chromium increases the metal's hardness.
A. Added
B. In addition
C. Adding
D. Adds
30.Bob was lying on the beach, his hands_________under his head.
A. were crossing
B. were crossed
C. crossing
D. crossed
31.Many strange new means of transport have been developed in our century, the strangest of them_________perhaps the hovercraft.
A. is
B. being
C. will be
D. has been
32.No one else_________willing to go, he offered to take the message.
A. was
B. had been
C. were
D. being
33._________, a man who expresses himself effectively is sure to succeed more rapidly than a man whose command of language is poor.
A. Other things being equal
B. Were other things equal
C. To be equal to other things
D. Other things to be equal
34.Maggie ran back to the kitchen, eggs_________carefully in her hands.
A. to be held
B. held
C. were held
D. holding
35.Agriculture is the country's chief source of wealth, wheat _________by far the biggest cereal crop.
A. is
B. being
C. has been
D. to be
36.All things _________, the planned trip will have to be called off.
A. considered
B. be considered
C. considering
D. having considered
三、单项选择（分词的完成式）。
37.A new technique _________, the yields as whole increased by 20 percent.
A. working out
B. having been worked out
C. having worked out
D. to have been worked out
38. _________that everything was in place, he locked up the shop and went home.
A. Checking
B. Having checked
C. Being checked
D. Having been checked
39.The dying soldier had the message_________straight to the commander.
A. sent
B. to be sent
C. be sent
D. being sent
40. _________the earth to be flat, many feared that Columbus would fall off the edge of the earth.
A. Having believed
B. Believing
C. Believed
D. Being believed
41._________ many times in a row, the opponent decided to give up fighting.
A. Having defeated
B. Having been defeated
C. For having been defeated
D. As having been defeated
42.With production_________up steadily, the factory needs an ever-increasing supply of raw materials.
A. having gone
B. going
C. to go
D. having been going
43.The supermarket is very crowded on Sundays, with people _________.
A. going in and out
B. to go in and out
C. gone in and out
D. having gone in and out
44.The fog_________dense, all the planes were suspended.
A. is
B. was
C. being
D. having been
45.The decision _________, what is to be done now is how to carry it out.
A. been made
B. being made
C. having been made
D. being making
46.There seemed little hope that the explorer,_________in the tropical forest, would find his way through it.
A. to be deserted
B. having deserted
C. to have been deserted
D. having been deserted
47.The destructive fire _________, the firefighters recommended the occupants' getting an alarm device.
A. having been put out
B. being put out
C. had been put out
D. was put out
四、单项选择（分词作补足语）。
48.You will see this product_________wherever you go.
A. to be advertised
B. advertised
C. advertise
D. advertising
49.The manager promised to keep me_________of how our business was going on.
A. to be informed
B. on informing
C. informed
D. informing
50.Corn originated in the New World and thus was not known in Europe until Columbus found it_________in Cuba.
A. being cultivated
B. having cultivated
C. been cultivated
D. cultivating
51.When I caught him_________me, I stopped buying things there and started dealing with another shop.
A. cheat
B. cheating
C. to cheat
D. to be cheating
52.He was caught_________his classmate's money the other day.
A. to steal
B. stealing
C. to have stolen
D. having stolen
53.Mrs. Douglas unknowingly left a package_________on the shop counter.
A. laying
B. to lie
C. laid
D. lying
54.His remarks left me_________about his real purpose.
A. wondered
B. wonder
C. to wonder
D. wondering
55.Next time I catch you _________, I'11 turn you in to the police.
A. stealing from others' pockets
B. steal from other's pockets
C. stealing other's pockets
D. to steal from other's pockets
56.They'11 have you_________if you don't pay your taxes.
A. to be arrested
B. arrested
C. arrest
D. being arrested
57.— There is something wrong with the table.
— yes, I can _________.
A. feel it that it's moving
B. feel it moves
C. feel it moving
D. feel it to move
58.The hall was too noisy for the speaker to make himself _________.
A. hear
B. hearing
C. being heard
D. heard
五、动名词与现在分词的区别。
分析下列短文中-ing形式所充当的成分，并判断其是动名词还是现在分词。
Passage 1
Pavarotti, Opera Star Finds Creative Passion in Painting
Tenor Luciano Pavarotti holds a handkerchief whenever he sings in concert. Yet in real life he is more likely to be found holding a paintbrush. For his great love is painting vividly colored pictures of Italian villages and seascapes. What he likes best about painting is its contrast to opera, where the challenge is to use one's talents to bring to life the works of others. "When I finish a canvas, I feel I have created a world.”
Passage 2
Nobody Can Decipher My Handwriting
One of his friends came to him saying , "I have a brother living in the capital. Would you mind writing him a letter for me?”“But I don't think I have time to go to the city!" he said.
“I am not asking you to go to the city," the friend explained, "I only asked if you would be kind enough to write him a letter." "I understand you perfectly the first time," he replied, "But nobody can decipher（辨认） my handwriting except myself. So if I'm not there to read it to him, it's no use writing . That's why I say I am not going to the capital.”
Passage 3
Break the Ice
There was a mutual attraction between my sister and a trainee working at her office. However, both being shy, they could barely even speak to each other.
During an office party, my sister went into the kitchen to get a drink and the trainee followed. Opening the freezer, he took out some ice, placed it on the work surface and began smashing it with a tin of coffee. Smiling , he explained, "I just wanted to break the ice between us.”
六、分析下列句子中粗体部分的-ing结构是动名词复合结构还是分词短语，并翻译成汉语。
59.I don't see how you can avoid the matter being discussed .
60. The matter being discussed is of great importance to your writing.
61. Children objecting to their parents' remarrying has become a social problem.
62. The children objecting to this proposal stand on the right, please.
63. The children objecting to this proposal surprised us all.
64. Children bringing newspapers can get $10 a day.
65.Last night I was awakened by someone tapping at the door .
66.I find myself resentful at having to talk to someone wearing sunglasses . Worst of all are those mirrored-lens sunglasses that, when you look into them, throw back two slightly distorted pictures of yourself.
67.I remember my parents taking me to the zoo.
68.When I was a child, I would take a flashlight to bed with me so that I could read comic books without my parents knowing about it.
69.The noise of the desks being opened and closed could be heard out in the street.
70.Along with approximately 180 soldiers, he chose to fight to the death against an army numbering in the thousands.
71.There was no chance of Davy emerging from the battle alive.
72.With the defenders refusing to raise the white flag, Santa Anna's soldiers would take no prisoners.
73.We were greatly encouraged by the news of China having launched another man-made satellite.
74.Anyone with half an eye on the unemployment figures knew that the assertion about economic recovery being just around the corner was untrue.
75.The eye of an animal is quite easy to see. How then can the eyes be prevented from spoiling the animal blending with its environment? One solution would be for the animal to keep its eyes closed when danger threatens.
七、辨别改错（分词构成复合形容词）。
76.In this way these insects show an efficient use of their sound-produced（A） ability, organizing（B） two sounds delivered（C） at a high rate as one call（D）.
77.If a hydrogen-filling（A） balloon is brought（B） near（C） a flame, it will explode（D）.
78.Were（A） the Times Co. to purchase another major media company, there is no doubt that it could（B） dramatically transform a family-ran（C） enterprise that still gets 90% of its（D） revenues from newspapers.
79.Because（A） the diamond is the hardest natural（B） occurring substance, it is used in industry for cutting（C）, grinding, and boring other hard（D） materials.
80.A great many（A） teachers firmly（B） believe that English is one of the poorest-taught（C） subjects in high schools at present（D）.
81.As long as（A） poor people, who in general are colored, are in conflict with（B） richer people, who in general are lighter（C） skin（D）, there's going to be a constant racial conflict in the world.
八、单项选择（综合练习）。
82.You would be_________if you thought that the problem was so cut and dried; in reality, it is much more complicated.
A. narrow-minded
B. narrow-minding
C. narrowly-mind
D. narrowly-minded
83. _______substances include various forms of silica, pumice, and emery.
A. Natural abrasives occur
B. Abrasion occurs in natural
C. Naturally occurring abrasive
D. A natural occurrence of abrasion
84.The_________economy at the turn of the century was due in large part to the influx of thousands of immigrants.
A. rapid expanding
B. rapid expansion
C. rapidly expanding
D. rapid expand
85. ________an answer, they decided to send an express telegram to them.
A. Having received not
B. Not received
C. Received not
D. Not having received
86.Niagara Falls is a great tourist attraction,_________millions of visitors every year.
A. to draw
B. drawing
C. to be drawn
D. draws
87.Language is a highway,_________all people and all ages.
A. to link
B. linking
C. linked
D. links
88.The computer works very fast,_________data at the speed of light.
A. having handled
B. handling
C. handled
D. handles
89.Though_________no Japanese, Charles was able to communicate with them.
A. having understood
B. understanding
C. understood
D. being understood
90.This crop has similar qualities to the previous one,_________both wind-resistant and adapted to the same type of soil.
A. being
B. been
C. to be
D. having been
91.The speech which he made_________the project has bothered me greatly.
A. being concerned
B. concerned
C. be concerned
D. concerning
92.The question_________tomorrow is whether income tax should be increased.
A. to debate
B. to be debated
C. debated
D. that it will be debated
93.After a few rounds of talks, both sides regarded the territory dispute _________.
A. being settled
B. to be settled
C. had settled
D. as settled
94.As early as 1647 Ohio made a decision that free, tax-supported schools should be established in every town_________50 house-holds or more.
A. having
B. to have
C. to have had
D. having had
95.After the country won independence, great emphasis was laid on expanding education, with girls as well as boys_________to go to school.
A. to be encouraged
B. being encouraged
C. been encouraged
D. be encouraged
96.Don't get your schedule _________; stay with us in this class.
A. to change
B. changing
C. changed
D. change
97.No matter how frequently _________, the works of Beethoven always attract large audiences.
A. performing
B. performed
C. to be performed
D. being performed
98. ________with the picture, Mary tore it to pieces.
A. Dissatisfying thoroughly
B. To dissatisfy thoroughly
C. Being thoroughly dissatisfied
D. To be thoroughly dissatisfied
99. ________with the size of the whole earth, the highest mountain does not seem high at all.
A. When compared
B. Compare
C. While comparing
D. Comparing
100.The guard walked through the train_________everyone's ticket.
A. inspecting
B. inspected
C. being inspected
D. to be inspected
101. ________nothing to talk about, the head said goodbye and went out of the room.
A. There was
B. Being
C. As there being
D. There being
102._________, the price would be reasonable.
A. All things are considered
B. For all things consider
C. All things considered
D. If all things considered
103.Intended to display the work of twentieth-century artists, ________in 1929.
A. the opening of the Museum of Modern Art
B. so the Museum of Modern Art opened
C. why the Museum of Modern Art opened
D. the Museum of Modern Art opened
104. ________at the turn of the century, the Minnesota State Capital building is made of white granite and marble.
A. Erected
B. Was erected
C. To erect it
D. Erecting
105.Really? She had her driving license_________for reckless driving?
A. withdraw
B. withdrawing
C. withdrew
D. withdrawn
106.With such a strong wind _________, the wire may break at any time.
A. blows
B. blowing
C. blew
D. is blowing
107. ________left before the deadline, I am afraid I can't finish the experiment on time.
A. Although such a short time
B. It is such a short time
C. With so short time
D. With such a short time
108.We have to go to other places to find a crane, there_________no crane here that stands idle.
A. is
B. to be
C. being
D. having been
109.The article opens and closes with descriptions of two news reports, each_________one major point in contrast with the other.
A. makes
B. made
C. is to make
D. making
110.As a pianist, he can hardly stand hearing a piano_________so badly.
A. playing
B. being played
C. to play
D. having played
111. ________of the burden of ice, the balloon climbed up and drifted to the South.
A. To be free
B. Freeing
C. To free
D. Freed
112.Geophysicists have collaborated with archaeologists and anthropo-logists to study the magnetic properties of pottery and fireplaces at sites_________by early humans.
A. occupied
B. occupying
C. which occupy
D. were occupied
113.During the course of its growth, a frog undergoes a true metamor-phosis_________with a fishlike larval stage.
A. begin
B. began
C. beginning
D. is begun
114._________, you should have no trouble with the difficult work.
A. Knowing this
B. If you are knowing this
C. From knowing this
D. If you had known this
115.One should never lose one's heart when_________temporary difficulties.
A. confronted with
B. confront with
C. confronting with
D. confronted
116.The difference between a winner and loser is, when ________immense difficulties, the former never loses heart.
A. confronted with
B. confronting with
C. it is confronted with
D. confront with
117.The other two children and three of the adults also had wounds _________ surgery.
A. required
B. require
C. requiring
D. to require
118.A stream of volcanic lava flows differently,_________on the sort of ground it flows over.
A. to depend
B. depending
C. that depends
D. when it depended
119.Just as the value of a telephone network increases with each new phone_________to the system, so does the value of a computer system increase with each program that turns out.
A. adding
B. to have added
C. to add
D. added
120.To everybody's surprise, the meeting ended, with nothing _________.
A. settled
B. being settled
C. settling
D. to settle
121.These are examples of the problems_________by science that we in America and other societies face.
A. to be posed
B. that has been posed
C. posed
D. posing
122. ________from general worker-protection laws, women workers are also satisfied with special laws designed to protect them.
A. Being benefited
B. Benefiting
C. Benefited
D. Been benefited
123.Efforts should be made to cultivate a business and legal environ-ment_________fair competition between national industries and foreign-funded enterprises.
A. facilitate
B. facilitated
C. facilitating
D. to be facilitating
124.A similar system has been used to aid in the removal of brain tumors in children, a procedure_________extremely risky.
A. to be considered
B. considered
C. to have been considered
D. considering
125. ________any previous experience, John doesn't stand a chance of getting that job.
A. Not having
B. Not having had
C. Having not
D. Having not had
126.I picked my way through the wet grass, my feet_________the saturated soil.
A. sank into
B. to sink into
C. being sunk into
D. sinking into
127. ________the financial means to remain independent, Thomas Edison was compelled to seek employment as a night telegraph operator.
A. He was deprived of
B. That he was deprived of
C. Although he was deprived of
D. Deprived of
128.Everything_________into consideration, Bob is more suitable for the job.
A. taking
B. being taken
C. to be taken
D. taken
129.Electrical resistance is a common property of all materials, _________.
A. differ only in degree
B. only in degree it differs
C. it only differs in degree
D. differing only in degree
130. ________for her anthropological research, Miss Mead also was involved with the World Federation Mental Health.
A. Noted primarily
B. Noting primarily
C. Being primarily noted
D. Having primarily noted
131._________, she went back to her room.
A. There was no cause for alarm
B. There being no cause for alarm
C. There be no cause for alarm
D. There has been no cause for alarm
132.The human skeleton consists of more than two hundred bones _________ together by tough and relatively inelastic connective tissues called ligaments.
A. bound
B. to bind
C. binding
D. bind them
133.The criticism threw new light on the novel and the students found themselves_________it with fresh eyes.
A. read
B. reading
C. to read
D. having read
134.The carat,_________as a unit for weighing gems, derived its name from the Greek word for the carob bean, a small weight.
A. is still used
B. still used
C. still is used
D. it is still used
135.Anna was reading a piece of science fiction, completely ________to the outside world.
A. being lost
B. having lost
C. losing
D. lost
136.He wasn't asked to take on the chairmanship of the society, _________ insufficiently popular with all members.
A. being considered
B. considering
C. to be considered
D. having considered
137.With age, the mineral content of human bones decreases, ________them more fragile.
A. make
B. and to make
C. thereby making
D. which it makes
138.Alaska found the first years of its statehood costly because it had to take over the expense of services_________previously by the federal government.
A. to be provided
B. being provided
C. provided
D. providing
139. ________363 miles between the cities of Albany and Buffalo in New York State, the Erie Canal helped link the Atlantic Ocean with the Great Lakes.
A. The extension of
B. The extension
C. Extending
D. Extends
140.It's easy to blame the decline of conversation on the pace of modern life and on the vague changes_________place in our ever-changing world.
A. taking
B. to take
C. take
D. taken
141.Only a small portion of college youth have actually been drafted and sent to fight in Vietnam, as_________to the nation's previous wars.
A. compared
B. comparing
C. comparison
D. being compared
142.Though_________in San Francisco, Dave had always preferred to record the plain facts of small-town life.
A. raised
B. grown
C. developed
D. cultivated
九、单项选择（提高题）。
143.The vocabulary and grammatical differences between British and American English are so trivial and few as hardly _________.
A. noticed
B. to be noticed
C. being noticed
D. to notice
144.The house was very quiet,_________as it was on the side of a mountain.
A. isolated
B. isolating
C. being isolated
D. having been isolated
145. ________as it was at such a time, his work attracted much attention.
A. Being published
B. Published
C. Publishing
D. To be published
146.First designated in 1970, Earth Day has become an annual interna-tional event_________concerns about environmental issues such as pollution.
A. dedicated to raising
B. dedicated raising
C. dedicates to raise
D. that dedicates to raising
147.The country's chief exports are iron ore, coal, wool and cotton goods, wool_________the most important of these.
A. has been
B. is
C. being
D. is being
148.With all the work _________, I don't know if I'11 have time to go out.
A. done
B. to be done
C. to do
D. doing
E. being done
149.I eventually found her_________with her friends in a pub.
A. sit chatting
B. sitting to chat
C. sitting chatting
D. sit to chat
150.In Europe it is quite usual to cross your legs when you are sitting _________ to someone even at an important meeting.
A. to talk
B. to talking
C. talking
D. for talking
151.Along the rocky New England coast are small areas of sand gravel beach, some created from debris,_________by the action of ocean storms.
A. others build up
B. others built up
C. others are build up
D. others were built up
152.She answered the door_________a magazine she _________.
A. carried, read
B. carrying, had been reading
C. carried, was reading
D. carrying, had read
153.The sale usually takes place outside the house, with the audience _________ on benches, chairs or boxes.
A. having seated
B. seating
C. seated
D. having been seated
154.All flights_________because of the storm, they decided to take the train.
A. having canceled
B. have been canceled
C. having been canceled
D. were canceled
155.There was a very interesting remark in a book by an Englishman that I read recently_________what he thought was a reason for this American characteristic.
A. giving
B. gave
C. to give
D. given
156.Peter went to the Congress very early,_________to push out the dissidents as many as he could.
A. his mind being made up
B. with his mind made up
C. with his mind making up
D. his mind making up
157.He smiled, stared at her hand for a moment, then_________away quickly.
A. walked
B. walking
C. to walk
D. walks
158.The delegates were seen_________in the hall but they didn't make known the problems _________.
A. be assembling, discussed
B. assembling, discussed
C. assembled, discussing
D. being assembled, discussing
159.How many of us _________, say, a meeting that is irrelevant to us would be interested in the discussion?
A. attended
B. attending
C. to attend
D. have attended
160.Anyone with half an eye on the unemployment figures knew that the assertion about economic recovery_________just around the corner was untrue.
A. would be
B. to be
C. was
D. being
161.The letters of Abigail Adams to her husband and future President, John,_________during the American Revolution, conveyed a vivid picture of the times.
A. were written
B. which written
C. written
D. written when
162.Relative humidity is the amount of water vapor the air contains at a certain temperature_________with the amount it could hold at that temperature.
A. to compare
B. compared
C. comparing
D. compares
163.All eels spawn in the sea, the eggs hatching into transparent, ribbon-like larvae _________, feeding until they metamorphose into small eels.
A. that drift about
B. drift about
C. about drifting
D. drift about them
164.Founded around 1075, the Acoma Pueblo is considered ________settlement in the United States.
A. the oldest continuously occupied
B. occupied continuously the oldest
C. the oldest occupied continuously
D. continuously the oldest occupied
十、辨别改错。
165.The Portuguese give（A） a great deal of credit to one man（B） for having promoted（C） sea travel, that man was（D） Prince Henry the navigator, who lived in the 15th century.
166.Beethoven, the great musician, wrote（A） nine symphonies in his life, most of them were written（B） after he had lost（C） his hearing（D）.
167.Writing（A） in verse, lucid style, the book describes the author's childhood（B） experiences（C） in Louisiana just before outbreak（D） of the Civil War.
168.Founded（A） in 1961 and employed（B） an estimated（C） 35,000 people, the organization has gained a reputation for brutality（D）.
169.He cannot tell the difference between true（A） praise and flattering（B） statements making（C） only to gain（D） his favor.
170.Whenever we hear of（A） a natural disaster, even（B） in a distant part of the world, we feel sympathy（C） for the people to have affected（D）.
171.In the teaching of（A） mathematics, the way of instruction is generally traditional, with（B） teachers presenting formal（C） lectures and students take（D） notes.
172.The conveniences that Americans desire reflecting（A） not so much a leisurely（B） lifestyle as a busy lifestyle in which even minutes of time are（C） too valuable to be wasted（D）.
173.The universe works in a way so far remove（A） from what common sense would（B） allow that（C） words of any kind must necessarily be inadequate to explain it（D）.
174.The Committee adopted a resolution requiring（A） the seven automakers selling（B） the most cars in the state making（C） 2 percent of those vehicles emissions-free（D） by 1998.
175.Plants synthesize（A） carbohydrates from water and carbon dioxide with the aid（B） of energy is derived（C） from sunlight（D）.
176.Charlotte Perkins Gilman is known primarily（A） as an author of short（D） stories, but she also wrote an influential book argued（C） for equal（D） economic opportunities for women.
177.Government money appropriated for art（A） in the 1930s made possible（B） hundreds of murals and statues still admiration（C） in small towns all over（D） the United States.
178.Ulysses S. Kay was among the（A） United States composers visited（B） the Soviet Union in 1958 to participate（C） in a cultural exchange program（D）.
179.Carrie Chapman was instrumental（A） in passing（B） the Nineteenth Amendment to the United States Constitution gives（C） women the right to vote（D）.
180.Carrie Chapman organized（A） the League of Women Voters after（B） successfully campaign（C） for the constitutional amendment that gave（D） women the right to vote.
181.With（A） production having gone up（B） steadily, the factory needs an ever-increasing（C） supply of（D） raw materials.
182.Financier Andrew Mellon donated（A） most of his magnificent art collection（B） to the National Gallery of Art, where（C） it is now locating（D）.
183.Like all ecological systems, a forest is made up of（A） a living environ-ment and a nonliving environment, the latter（B） is composed of（C） air, rocks（D）, soil, and water.
184.Won（A） its war for independence in 1783, the United States then struggled to establish（B） its own（C） economic and financial system（D）.
185.Bacteria lived（A） in the soil play（B） a vital role in recycling（C） the carbon and nitrogen needed（D） by plants.
186.Some（A） snakes have hollow teeth are called（B） fangs that they（C） use to poison（D） their victims.
187.Compare（A） with the jagged（B） estuaries（C） of the Atlantic coast, the Pacific coast seems almost uniformly（D） straight.
188.Discovery（A） in 1789 and（B） isolated from（C） other elements in 1841, uranium is valued as（D） a source of atomic energy.
189.Celery, an edible（A） plant is having（B） long stalks topped with（C） feathery leaves, grows best（D） in cool weather.
190.In 1862 Abraham Lincoln signed the Homestead Act, allows（A） settlers（B） 160 acres of free land（C） after they had worked it for（D） five years.
191.After（A） a heavy rain, a rainbow may spread all the way across（B） the sky, its two ends seem（C） to rest on（D） the Earth.